Tube base and socket



Oct'. 3, 1939. J. E. BEGGs TUBE vBASE AND SOCKET Filed 001'.. 30, 193'.

James BBQ s,

HIS Attorney.

Patented Oct. 3, 1939 PATENT OFFICE TUBE BASE AND SOCKET James E. Beggs, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York l Application October 30, 1937, Serial No. 171,938

10 Claims.

The present invention relates to radio tubes, more particularly to the contact pin and base assembly for making connection between the elements of the tube and the external circuits.

In the prior forms of tube bases, it has been customary to provide contact pins molded in a base of insulating material and to connect these pins through flexible leading-in conductors with the electrodes. For locating the tube with respect to the socket, a centrally mounted hollow locating pin is molded on the base. The base also carries an evacuating tubulation, which, in the case of a metal tube, is generally made of metal. This tubulation is usually contained within the hollow locating pin and thus is hidden from view. It is apparent that a base and contact pin arrangement of this type is expensive to make and assemble, and an object of the present invention is to simplify the construction to the end that the cost of manufacturing the entire tube is reduced.

In accordance with this object, an improved form of base is provided in that the base is made of metal'and not only carries contact and locating pins but also constitutes the hermetic closure for the envelope. Thus all molded material, including the molded locating pin, is eliminated. 'I'he contact pins are formed as continuations of the leading-in conductors, and the evacuating tubulation is so disposed as to serve as a combined terminal and' pin for locating the tube with respect to the socket. The invention will be better understood when read in connection with the following specification and the accompanying drawing in which Fig. 1 is a view taken along line l--I of Fig. 2 and partly in section, of a combined tube, base and socket assembly improved in accordance with the present invention. Fig. 2 is a fragmentary plan view of the socket. Fig. 3 is a perspective view of a clamp terminal which is employed to contact with the evacuating tubulation. Figs. 4, 5,6 and 7 are sectional views, partly in elevation of several types of combined leading-in conductor and contact pin structures, while Figs. 8, 9 and 10 are sectional views of several types of combined evacuating tubulation and locating pin assemblies.

Referring more particuarly to Fig. l, numeral I designates a cylinder consisting of any readily workable, inexpensive metal such as iron, nickel, etc. which is closed at the top (as shown) and terminates at the bottom in a flared rim 2. There is secured to this rim, as by welding, a fiat metal plate 3 which will be referred to hereinafter as a base, since as will be explained, it serves all of the purposes of the usual bases. The envelope l u contains one or more electrodes (not shown), in-

(Cl. Z50- 275) cluding a cathode, and conductors l are taken from each of these electrodes through the base member, in a manner to be described, to the exterior. For carrying these conductors through the base member 3 in an insulating manner, openings are provided and flanged metal eyelets 5 secured to the base about each of the openings. The flange of each eyelet is secured either to the upper or lower surface of the base member and is preferably welded thereto. Insulating material such as glass 6 is provided between each leading-in conductor and the surrounding eyelet. In order to insure a permanent vacuum-tight seal between the glass and the eyelet, these members should preferably have substantially the same thermal expansion characteristic over the entire temperature range between C. and the softening temperature of the glass. Such materials are well known in the art and examples thereof are set forth in the Burger and Hull Patent No. 2,071,196. As shown more particularly in Fig. 4, the leadingin conductor 4 is extended through the glass 6 and terminates in an enlarged portion 1 which is of a diameter sufficiently large to make good contact with openings in a metal socket member which will be described presently. The enlarged portion l terminates at the end remote from the base 3 in a rounded blunt portion to facilitate the entry of the portion 1 into the socket opening. The enarged portion l is conveniently fabricated as a separate member and then butt-welded to the conductor l, as shown in Fig. 4. l

Fig. 5 shows 4a modied form of Contact pin construction in which the leading-in conductor 4 is provided with a reduced diameter portion 9 immediately adjacent the pin. The purpose of the portion 9 is to give flexibility to the combined pin and conductor so that any force applied laterally to the pin, as when the pin is being forced into a socket opening, will tend to bend the conductor at the constricted portion rather than at any portion which is contained Within the glass. Thus the seal is not deleteriously affected or strained under these conditions.

Fig. 6 shows still another modification of lead and pin construction in that the pin l is provided with a hole along its axis and the conductor 4 is extended to enter the hole and secured to the pin by soldering or welding. As in the case of Fig. 5, the conductor may be provided with a portion of restricted diameter if desired.

Fig. 7 shows another modified form of pin and conductor structure in that the conductor is provided with an enlarged portion l2 at the place where the conductor is sealed in the glass, so that the length of the conductor between the enlarged portion and the pin constitutes, in effect, a reduced diameter portion about which the entire structure will bend in case the pin is laterally strained. The pin may be secured to the conductor by buttwelding or by means of an opening through which the conductor passes.

In order to provide for pumping the envelope interior, a hollow metal tubulation I3, anged at the upper end (as shown) is welded to the base member 3. After the envelope interior has been evacuated, the lower end 33 of the tubulation is iiattened and welded tightly so as to form a hermetic seal. A section of the Welded and flattened tubulation is shown in Fig. 8. The metal tubulation including the iiattened end portion 33 serves not only as a terminal for making connection to the envelope but also as a pin for locating the tube and its base member with respect to the socket.

Instead of providing an all-metal evacuating tubulation, a composite structure of glass and metal may also be employed. Thus in Fig. 9, an eyelet I4 may be welded to the under side of the base member 3 about the evacuation opening. A glass tip I5 is sealed to the lower edge of the eyelet so that after the tube interior has been evacuated, the tip may be fused to close the opening. The metal eyelet I4 and glass tip I5 should preferably have the same coeiiicient of thermal expansion up to and including the softening temperature of the glass. In order to protect the glass tip from fracture, a cover or shield member I6 of metal may be welded or soldered to a iiange i'I which extends downwardly from the peripheral edge of the eyelet. The member I6 can be employed as a terminal or a pin for locating the base with respect to the socket.

Fig. shows still another form of combined exhaust tubulation, terminal and locating pin but in this case the element is made entirely of metal. The tubulation is provided at its upper edge with an outwardly extending flange which may be secured to the base member 3 at the exhaust opening. For closing the end of the member I8 opposite to the base 3, a metal ball element i 9 may be employed. This ball has a diameter to correspond with the arcuate surfaces provided at the end of the tube I8. The ball may be rolled into position in any suitable and well known manner after the tube has been evacuated and is rigidly held in place by solder or a weld. Suitable adaptors which will be described presently are provided on the socket to accommodate these various forms of tubulations.

'I'he socket consists essentially of two heavy layers of varnished cambric which may be secured together and to a base plate or frame 2i of a radio set by a screw and nut arrangement 22. Openings 23 are provided in each layer of cambric andA positioned around a circle corresponding to' the position of the contact pins 'I on the base member 3. An opening 24 of larger diameter is also provided at a position corresponding to the position of the tubulation I3. There is a metal collar 25 about each opening 23 having a lengthwise slit 26 and held in position by an extension 21 which is secured in any suitable manner between the layers 2li. The end of the strip 21 opposite from the collar 25 is extended outwardly and downwardly from the base as shown at 28 to constitute a terminal to which conductors can be secured. The diametral size of the collar 25 is such as to grip the pin 'I tightly when the base member is inserted into the socket.

For accommodating the evacuating tubulation in the socket, a structure such as that shown in Fig. 3 may be provided. This structure takes the general form of a clamp 33 of spring steel having two legs 3l which are sprung open by a spacer member 32. 'Ihe distance between the legs 3| is such as to grip the ilattened portion 33 of the evacuating tubulation shown in Fig. 8, or to `grip the round portions oi' the tubulations shown in Figs. 9 and 10. The legs II are restrained from opening too far by a metal U-shaped member 3| which is secured as by welding to the member 3l and which tends normally to press the legs 3| together. For mounting the clamp member on the socket, a transversely extending member is provided which has an opening for receiving a rivet 3G or a screw. An extension 31 is provided on the clamp to facilitate connection with an external conductor.

It is apparent from the foregoing description that I have disclosed an improved form of contact pin and socket structure in which the contact pins constitute a continuation of the leadingin conductors and are rigidly secured thereto, and these contact pins are received by the metal collars 25 in the improved form of socket to which external connections can be made. It is also apparent that I have disclosed an improved form of locating pin in which the same element which serves for evacuation purposes is also used as a terminal and pin for locating the base with respectto the openings in the socket. Since the openings 23, 24 are of different size, it would be impossible to insert the pins into the wrong openings. It will also be noted that the contact pin and locating pin arrangement is such, particularly the manner in which these members are secured directly to the metal base 3, that there is no necessity for a base of insulating material such as is usually provided with tubes of this character. The entire contact pin and locating pin assembly is carried solely by the base 3 which also serves the function of hermetically closing the open end of the. envelope I.

While I have described the improved pin and socket arrangement in connection with a metal tube, it will be understood that the improvement can be used successfully with tubes of the glass type, in which case the base 3 is made of a metal havingsubstantially the same coeiiicient of expansion as the glass envelope so as to be satisfactorily sealed thereto.

What I claim as new and desire to secure by Letters Patent in the United States is:

1. A base for an electric discharge device adapted to be mounted in a socket, said base comprising a metal disk adapted to be secured to said device, said disk carrying a leading-in conductor having a rigid end portion to serve as a contact pin, said disk also carrying a metal evacuating tubulation adapted to serve as a pin for locating the base with respect to said socket.

2. A base for an electric discharge device of the metal type and adapted to be mounted in a socket provided with contact members, said base comprising a metal disk adapted to be secured to said device and carrying a leading-in conductor, said conductor having a rigid end portion which is adapted to engage a contact member on said socket, said disk also carrying a metal evacuating tubulation which terminates in a flattened portion, said tubulation being adapted to engage another contact member on said socket and to serve as a pin for locating the tube with respect to said socket.

3. In combination, an electric discharge device, and a socket therefor, said tube being closed by a metal base member carrying a contact pin and a metal evacuation tubulation, means mounted on said socket for contacting said pin and tubulation, said tubulation-contacting means comprising a pair of metal spring members which press opposite sides of the tubulation.

4. In combination, an electric discharge device and a socket therefor, said device being closed by a metal base member carrying a contact pin and a metal evacuation tubulation, means mounted on said socket for contacting said pin and tubulation, said pin-contacting means comprising a metal tubing which grips the pin, and said tubulation-contacting means comprising a spring member which presses against the tubulation.

5. A base for an electric discharge device comprising a metal disk adapted to be secured to said device, an opening in said disk, a metal eyelet secured to said disk about the opening, a leading-in conductor passing through said eyelet and insulatlngly sealed therein, said conductor terminating in an enlarged portion which serves as a contact pin, the portion of conductor which is sealed in said eyelet being of larger size than the portion of conductor immediately adjacent said enlarged contact pin portion.

6. In combination, a base for an electric discharge device, said base comprising a metal disk adapted to be secured to said device, said disk carrying a leading-in conductor having a rigid end portion to serve as a contact pin, said disk also carrying a metal evacuating tubulation adapted to serve as a contact pin, said'tubulation being of a size different from said pin, and a socket for receiving the contact pin and tubulation, said socket being provided with openings of sizes corresponding to the sizes of said pin and tubulation.

'7. A base for an electric discharge device, said base comprising a metal disk adapted to be secured to said device, said disk carrying a contact pin and an evacuating tubulation, said tubulation comprising glass and metal portions, and a metal member surrounding the glass portion, said member being adapted to serve as a contact pin.

8. A base for an electric discharge device comprising a disk adapted to be secured to said device, a leading-in conductor insulatingly secured to said disk, said conductor having two portions which are respectively of larger and smaller size than the remainder ofthe conductor, the portion of larger size constituting a contact pin for said device and the portion of smaller size constituting a flexible section which can be readily bent when lateral force is applied against said pin.

9. An electric discharge device comprising an envelope which encloses electrode structure and which is provided with a flattened wall portion, lead-in conductors extending through said wall portion and shaped at their outer extremities to serve as contact pins, and fusible vitreous material sealed to the said conductors for insulatingly supporting the same at the region of their passage through the said wall portion, each conductor being provided with a section of materially reduced diameter between the outer extremity of the conductor and the region of its conjunction with the said vitreous material whereby suflicient lateral exing of the conductor may occur at such section to protect the vitreous material from fracture during engagement of the conductor extremity with a socket terminal or the like.

10. An electric discharge device comprising an envelope which encloses electrode structure and which is provided with a flattened wall portion, lead-in conductors projecting outwardly through said wall portion and shaped at their outer extremities as contact pins, and an evacuating tubulation mounted on said wall portion and arranged substantially parallel to the lead-in conductors, the tubulation being of length comparable with the outwardly projecting portions of the lead-in conductors but being of different cross-sectional dimensions than the said contact pins, whereby it is adapted to serve as a guide means for orienting the device in a socket having openings which are shaped selectively to receive the tubulation and contact pins.

JAMES E. BEGGS. 

